For those who want to improve their fuel economy, or are wondering why it's not as good as it ought to be...

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5
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3answers
1k views

why do engines have so much unused horsepower?

I've looked at the power rating of an engine used in a Humvee (5500 lbs) and was surprised it's only ~190 horsepower, which is exceeded by many 4 door sedans. So an obvious question is why doesn't my ...
0
votes
2answers
909 views

What would cause a 2003 Kia Sedona to have bad fuel economy?

I have 2003 Kia Sedona 2.5 liter AT in good condition. I've replaced some of the old parts with new ones. Both highway and city fuel consumption is bad compared to other cars with same engine ...
8
votes
2answers
2k views

Low power, bad gas mileage, smelly exhaust after engine work

My 92 Civic has had low power (need to use at least one gear lower than usual to get the same power) and has been getting bad gas mileage (15-25mpg vs 32-42 mpg usual) since I replaced the head ...
5
votes
2answers
310 views

When do engine type and mileage of a car affect pricing?

I'm currently designing a customer relationship management tool for auto shop owners and was wondering: Does engine type or the odometer value of a car ever affect pricing for a customer? What ...
2
votes
5answers
6k views

How to save fuel on downhill slopes on a motorcycle: clutch or neutral?

I have a two wheeler i.e. bike (Honda company, four stroke) which has four gear. While driving my bike, when I come to downhill slopes, I shift the motorcycle to neutral to save the fuel. (The slopes ...
2
votes
3answers
86 views

Alternate fuel for motor cyce

In some countries, Government mixes ethanol with petrol & diesel and distributes it to their consumers. This will save some of their imports. My question is Can I blend petrol with Zatropha ...
5
votes
2answers
7k views

Why does my engine perform poorly and get bad gas mileage after using fuel injector cleaner?

At the advice of someone at a local auto parts shop, I poured a bottle of fuel injector cleaner into my gas tank. This happened around the same time that I had a brake job done and rotated my tires. ...
1
vote
2answers
1k views

How much efficiency is robbed from 'pumping loss,' if any?

I'm specifically referring to the loss due to the pistons pulling air through a mostly closed throttle while cruising at highway speeds in a gasoline engine. To give an example, I've always wondered ...
6
votes
2answers
1k views

Pulsar 180 - How Can I Measure the Mileage?

Could anybody please tell me how to measure the mileage of my Pulsar 180 bike accurately? I have tried by emptying my tank. I failed miserably, and I had to take my bike walking long distance.
0
votes
2answers
537 views

Torque App Mileage reliability?

I am using an OBD-II sensor and the Andriod Torque app to look at my fuel economy and see that it shows a whopping 37 MPG for my Mazda 6, 2005 (2.3 Automatic). This seems fishy as some random googling ...
4
votes
5answers
697 views

Can I save money using E85 in my flexible fuel vehicle?

Where E85 Ethanol is available (not very common), the price per gallon is often lower than regular unleaded gasoline. Though I've read that fuel economy is commonly reduced by 20% or more, when using ...
6
votes
4answers
923 views

Are there any disadvantage to fuel efficient tires?

I'm in need of new tires and I saw some fuel efficient/low rolling resistance tires. Is there any disadvantage to this type of tire?
11
votes
6answers
10k views

How to improve fuel economy in high-mileage car?

I'm driving an 2003 Acura TL 3.2 with 177K miles on it. I bought the car with 110K miles on it. It seems to me that the car is not getting the same fuel economy that it did when I acquired it. I ...
3
votes
3answers
113 views

improving fuel efficiency in a 96 taurus

I have a 1996 Ford Taurus with less than 200,00km on it I don't want to spend too much on it but want to improve the fuel efficiency on it. I do mostly highway driving with a bit of city driving. ...
3
votes
1answer
177 views

How much mpg am I losing with different inflated tires?

I have the front passenger side and rear driver side tires at 34 psi. The other two wheels are around 28. How much is this affecting the mileage on the car? It is a 2004 Cadillac SRX V8, and the ...
4
votes
3answers
9k views

Effect of loss of fuel tank vapours on mileage

Are there any estimates available on how much fuel you can expect to lose from a fuel tank that is leaking vapours? Leaking vapours would be caused by cracked/missing evaporative emissions hoses, a ...
7
votes
3answers
140 views

Gas mileage down significantly the last few tanks: what should I look for?

The gas mileage in my car is degraded significantly the last three tanks. What should I look for? Details of the vehicle are below, but this question could also apply to anyone who sees this problem ...
6
votes
5answers
5k views

Fuel efficiency and Shifting/RPM

I was reading a thread in a car forum where someone wrote: The lower the RPM, the less fuel you use, the less strain you put on everything.. Another person then replied, stating: Not true. ...
0
votes
1answer
401 views

What's the catch in Ford Mondeo Econetic driving at 3 liters per 100 kilometers story?

News report (here and here and lots more can be found that two guys drove Ford Mondeo Econetic with 1,6 liters diesel engine and got fuel consumption of about 3 liters per 100 kilometers. That's ...
15
votes
7answers
58k views

Is idling bad for your engine?

If I sit in my car for 30-40 minutes with the AC and the car idling, does that "hurt" the engine, or does it simply waste gas and pollute the air? Would it be better if I turned off the car? A ...
6
votes
2answers
12k views

Engine Size and Fuel Consumption

I have this weird misconception that the engine size is related to the amount of fuel being burned in one cycle(4-stroke engine). I know this is stupid but how does engine size relate to the amount of ...
5
votes
4answers
2k views

Does the tachometer provide any indication of fuel usage?

So, I'm driving along on the highway with the A/C blasting when I notice the price of gas. It makes me think, "what can I do to increase my fuel efficiency?" Some of the tips I've heard have included ...
9
votes
3answers
1k views

Are there any advantages of idling a vehicle vs. turning it off and back on again?

I was sitting outside, eating my lunch the other day, and a small bus (you know, one of the short ones) pulled up to the sandwich shop I was eating at. I noticed that the driver got out of the bus, ...
8
votes
1answer
675 views

how can I measure the amount of fuel injected into a diesel engine in real time in a purely mechanic pre-OBD vehicle?

This is a Mercedes-Benz 308D van, year 1992, model 602.316. Pre-OBD, no electronics of any sort, everything is purely mechanical. I would like to retrofit a system which would measure the precise ...
10
votes
1answer
3k views

how to optimize fuel consumption by changing the rear differential ratio?

Is it possible to improve the fuel consumption (decrease it) in my van by changing the rear differential ratio? I would like to optimize it for low-speed driving about 40 km/h (25 mph). Is it true ...